What is generalised hyperhidrosis?

Hyperhidrosis is a condition characterised by excessive sweating; that is, the production of more sweat than is required to regulate body temperature. It is caused by non-thermoregulatory stimuli, meaning stimuli other than heat. Normally the body only sweats when it becomes hot.
Generalised hyperhidrosis refers to hyperhidrosis affecting the entire body. It is also known as secondary hyperhidrosis as it typically arises secondary to other medical conditions, predominately endocrinological (hormone-related) and infectious disorders. Generalised hyperhidrosis may also occur due to dysregulation of the autonomic nervous system, or neurological disorders such as Parkinson’s disease or spinal cord injury.
While hyperhidrosis which manifests secondary to (as a result of) another medical disorder typically affects the entire body, it may also occur at distinct anatomical sites. Generalised hyperhidrosis affecting distinct sites rarely arises secondary to a disease and is usually a result of:

Statistics on generalised hyperhidrosis

Generalised hyperhidrosis often manifests secondary to another medical condition; however, not all individuals with a particular condition will experience hyperhidrosis. For example, amongst patients with Hodgkin’s lymphoma some 25% experience excessive sweating.
Amongst menopausal women, 79% in the peri-menopause (the period of time leading up to the final menstrual period) and 65% in the post-menopause (after the final menstrual period) experience vasomotor symptoms of menopause which cause excessive sweating, frequently night sweats.

Risk factors for generalised hyperhidrosis

An underlying medical condition is the key factor that predisposes an individual to generalised hyperhidrosis.

Progression of generalised hyperhidrosis

Generalised hyperhidrosis usually begins in adulthood due to medical comorbidity; that is, a disease which causes the excessive sweating (e.g. infection). It typically resolves following treatment of the comorbid condition.

Symptoms of generalised hyperhidrosis

When diagnosing generalised hyperhidrosis, the doctor will ask questions about sweating, for example how often it occurs and when it began, to determine whether or not the sweating is excessive, and to differentiate between focal and generalised hyperhidrosis. The doctor may ask about

The duration since onset of excessive sweating;

Age at onset, with childhood or adolescent onset suggesting focal hyperhidrosis;

Family history of the condition, with a positive family history indicating focal hyperhidrosis;

The site of excessive sweating, with hyperhidrosis at distinct anatomical sites (commonly the arms, feet, armpits and face) indicating focal hyperhidrosis and hyperhidrosis affecting the entire body indicative of generalised hyperhidrosis;

Experience of nocturnal (night time) sweating, with history of nocturnal sweating indicating generalised and its absence strongly suggesting focal hyperhidrosis;

A simple scale such as the hyperhidrosis severity scale, which asks individuals to rate the severity of their symptoms on a four-point scale, may be useful.

Hyperhidrosis severity scale tool

How would you rate the severity of your excessive sweating?

Select the response which best describes your sweating:

If you are using the tool to monitor the effect of treatment, validation studies of this severity scale show that a one-point reduction in severity is associated with a 50% reduction in sweating. A two-point reduction is associated with an 80% reduction in sweating.

Generalised hyperhidrosis affects the entire body and typically occurs diurnally (in the day) and nocturnally. Following a diagnosis of generalised or secondary hyperhidrosis, further tests are used to diagnose the underlying medical condition/s, as treating these conditions is the only way to reduce the excessive sweating. The doctor will consider a range of possible conditions which are commonly associated with generalised hyperhidrosis, including:

Toxicity from alcohol or other substances may also cause hyperhidrosis, as may withdrawal from alcohol or other substances in dependent individuals. Some medications are also implicated in generalised hyperhidrosis, including:

In order to identify conditions which might underlie generalised hyperhidrosis and propose appropriate tests to conduct, the doctor is also likely to ask questions about your general health and other symptoms. Symptoms which may indicate a particular diagnosis include:

Sustained or paroxysmal (episodic) hypertension in a person with generalised hyperhidrosis suggests the need for further investigations to confirm or exclude paragangliomas (usually benign tumour of the neurological tissue) and phaeochromocytomas (paragangliomas which grow in the adrenal gland).

Hyperhidrosis has similar symptoms to menopausal hot flushes. Menopausal women should not, however, assume there excessive sweating symptoms are underpinned by menopause. It is important for these women to visit a doctor and ensure other conditions are not causing the sweating.

Clinical examination of generalised hyperhidrosis

The doctor may also conduct a physical examination for signs of hyperhidrosis such as visibly damp clothing, and complications arising from constant dampness including maceration (softening of the skin) and fungal infection.

How is generalised hyperhidrosis diagnosed?

The doctor may also wish to conduct tests to ensure the underlying condition is correctly diagnosed. The choice of tests depends on the condition suspected to be causing excessive sweating.

Blood tests

Blood test may be used to assist in diagnosing a range of conditions which commonly underlie generalised hyperhidrosis, including:

Menopause: In women of menopausal age, hormone levels in blood may be measured to confirm menopausal status. In women who are approaching but have not yet experienced their final menstrual period, a series of blood tests may be conducted;

Hyperthyroidism: If hyperthyroidism is suspected, blood tests to measure thyroid hormones may be performed;

Blood disorders: Blood tests can be used to assist in the diagnosis of lymphoma and myeloproliferative disorders;

Infection.

Transthoracic echocardiogram

If endocarditis is suspected, an echocardiogram (ultrasound of the heart) may be conducted.

Chest radiograph

A chest radiograph may be performed in cases of suspected malignancy or tuberculosis.

Endocrinological investigations

If common endocrinological causes such as menopause and hyperthyroidism are excluded but an endocrinological cause is suspected, the individual may be referred for specialist assessment by an endocrinologist.

Prognosis of generalised hyperhidrosis

Generalised hyperhidrosis typically resolves when the underlying condition is treated.

Treatment of generalised hyperhidrosis

Because generalised hyperhidrosis usually arises secondary to a medical condition, investigation and treatment of the underlying condition is the first step in the management process. It is usually sufficient to resolve the underlying condition and excessive sweating symptoms. For example, in menopausal woman with hyperhidrosis, hormone replacement therapy may be used to resolve the condition. When medication use is the cause of generalised hyperhidrosis, adjustments to the medication regimen may lead to improvement of hyperhidrosis.
If treatment and medication adjustments do not resolve generalised hyperhidrosis, the doctor may prescribe a medicine which interferes with the sweating process.
In patients who do not respond to systemic treatments, treatments targeting the anatomical sites which are most prone to excessive sweating should be considered. Treatments indicated in focal hyperhidrosis such as surgery and botulinum toxin A injection (e.g. Botox and Dysport) may be instituted.